Organic chloramines of little disinfection efficacy commonly exist in disinfection process (chlor(am)ination) due to the wide presence of organic amines in water, of which N-chlorodimethylamine (CDMA) is a typical one. For the first time, UV photolysis for the activation of CDMA was investigated. UV photolysis caused the cleavage of N-Cl bond in CDMA to form Cl^• and subsequently HO^•, both of which are dominant contributors to the destruction of model contaminant bisphenol A (BPA). Typical spectra of HO^• were detected by electron paramagnetic resonance (EPR) experiments, while spectra of reactive nitrogen species (RNS) were not detected during UV photolysis of CDMA. The increase of pH (6.0–8.0), HCO₃⁻/CO₃²⁻, Cl⁻ and nature organic matter inhibited the degradation of BPA. We proposed pathways of CDMA and BPA degradation based on the identified transformation products. UV photolysis of CDMA and BPA reduced the formation of N-nitrosodimethylamine (NDMA) at pH 8.0, but increased the formation of trichloronitromethane (TCNM) at pH 7.0 and 8.0. The increasing toxicity and the formation of TCNM and NDMA gave us a hint that formation of organic chloramines should be concerned.

由于水中有机胺的广泛存在，消毒过程（氯（胺）化）中普遍存在消毒效果较差的有机氯胺，其中典型的有N-氯二甲胺（CDMA）。首次研究了用于激活 CDMA 的紫外光解。紫外光解导致 CDMA 中 N-Cl 键断裂形成 Cl ^•和随后的 H2O ^•，这两者都是破坏模型污染物双酚 A (BPA) 的主要因素。通过电子顺磁共振 (EPR) 实验检测到典型的 H2O ^•光谱，而在 CDMA 的紫外光解过程中未检测到活性氮物种 (RNS) 的光谱。pH 值增加 (6.0–8.0)，HCO ₃ ⁻/CO ₃ ^2-、Cl ^-和天然有机物抑制了BPA的降解。我们根据已识别的转换产物提出了 CDMA 和 BPA 退化的途径。CDMA 和 BPA 的紫外光解在 pH 8.0 时减少了N-亚硝基二甲胺 (NDMA) 的形成，但在 pH 7.0 和 8.0 时会增加三氯硝基甲烷 (TCNM) 的形成。毒性的增加以及 TCNM 和 NDMA 的形成提示我们应该关注有机氯胺的形成。